Spin relaxation times of two-dimensional holes from spin sensitive bleaching of intersubband absorption

Schneider, Petra; Kainz, J.; Ganichev, Sergey; Danilov, Sergey; Rößler, U.; Wegscheider, Werner; Weiss, Dieter; Prettl, Wilhelm; Belkov, Vassilij; Glazov, M. M.; Golub, L. E.; Schuh, Dieter

doi:10.1063/1.1753656

Cited by 62 publications

(65 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1(b). In (013)-oriented QWs, excitation by normally incident THz radiation results in a photogalvanic current even at B z = 0, [37][38][39] point group), the photocurrent has no predefined direction and its magnitude j = j 2 x + j 2 y can be deduced by measuring the signals along two orthogonal directions. 40 The current-induced photovoltages U x,y are picked up across a 1 M load resistor applying lock-in technique.…”

Section: Methodsmentioning

confidence: 99%

Giant photocurrents in a Dirac fermion system at cyclotron resonance

et al. 2013

Self Cite

View full text Add to dashboard Cite

We report on the observation of the giant photocurrents in HgTe/HgCdTe quantum well (QW) of critical thickness at which a Dirac spectrum emerges. At an exciting QW of 6.6 nm width by terahertz (THz) radiation and sweeping magnetic field we detected a resonant photocurrent. Remarkably, the position of the resonance can be tuned from negative (−0.4 T) to positive (up to 1.2 T) magnetic fields by means of optical doping. The photocurrent data, accompanied by measurements of radiation transmission as well as Shubnikov-de Haas and quantum Hall effects, prove that the photocurrent is caused by cyclotron resonance in a Dirac fermion system, which allows us to obtain the effective electron velocity v ≈ 7.2 × 10 5 m/s. We develop a microscopic theory of the effect and show that the inherent spin-dependent asymmetry of light-matter coupling in the system of Dirac fermions causes the electric current to flow.

show abstract

Section: Methodsmentioning

confidence: 99%

Giant photocurrents in a Dirac fermion system at cyclotron resonance

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Phenomenological and theoretical data for electron spin relaxation and for GaAs-GaAlAs QWs are included in many papers [29][30][31][32][33] . Also, data for hole spin flip times can be found in the literature [34][35][36] . An extensive analysis of the formation, recombination and dissociation coefficients can be found in the papers of Esser et al 1 and Portella-Oberli et al 4,37 .…”

Section: General Dynamicsmentioning

confidence: 99%

The role of excitons and trions on electron spin polarization in quantum wells

Aceituno¹,

Hernández‐Cabrera²

2011

Journal of Applied Physics

View full text Add to dashboard Cite

We have studied the time evolution of the electron spin polarization under continuous photoexcitation in remotely n-doped semiconductor quantum wells. The doped region allows us to get the necessary excess of free electrons to form trions. We have considered electron resonant photoexcitation at free, exciton and trion electron energy levels. Also, we have studied the relative effect of photoexcitation energy density and doping concentration. In order to obtain the two-dimensional density evolution of the different species, we have performed dynamic calculations through the matrix density formalism. Our results indicate that photoexcitation of free electron level leads to a higher spin polarization. Also, we have found that increasing the photoexcitation energy or diminishing the doping enhances spin polarization.

show abstract

“…Pulsed high-power THz radiation with f ≈ 2.03 THz (λ = 148 μm), a peak power P ≈ 40 kW at the sample spot, and a pulse duration of ≈200 ns is obtained by a NH 3 laser optically pumped with a TEA CO 2 laser. 28,29 In this setup, the signal is detected via a voltage drop over a 50-load resistor applying a fast amplifier and a storage oscilloscope. The radiation power has been controlled by either pyroelectric detectors or THz photon drag detector.…”

Section: Experimental Techniquementioning

confidence: 99%

Spin-polarized electric currents in diluted magnetic semiconductor heterostructures induced by terahertz and microwave radiation

et al. 2012

Self Cite

View full text Add to dashboard Cite

We report on the study of spin-polarized electric currents in diluted magnetic semiconductor (DMS) quantum wells subjected to an in-plane external magnetic field and illuminated by microwave or terahertz radiation. The effect is studied in (Cd,Mn)Te/(Cd,Mg)Te quantum-wells (QWs) and (In,Ga)As/InAlAs:Mn QWs belonging to the well-known II-VI and III-V DMS material systems, as well as in heterovalent AlSb/InAs/(Zn,Mn)Te QWs, which represent a promising combination of II-VI and III-V semiconductors. Experimental data and developed theory demonstrate that the photocurrent originates from a spin-dependent scattering of free carriers by static defects or phonons in the Drude absorption of radiation and subsequent relaxation of carriers. We show that in DMS structures, the efficiency of the current generation is drastically enhanced compared to nonmagnetic semiconductors. The enhancement is caused by the exchange interaction of carrier spins with localized spins of magnetic ions resulting, on the one hand, in the giant Zeeman spin splitting, and, on the other hand, in the spin-dependent carrier scattering by localized Mn 2+ ions polarized by an external magnetic field.

show abstract

Spin relaxation times of two-dimensional holes from spin sensitive bleaching of intersubband absorption

Cited by 62 publications

References 24 publications

Giant photocurrents in a Dirac fermion system at cyclotron resonance

Giant photocurrents in a Dirac fermion system at cyclotron resonance

The role of excitons and trions on electron spin polarization in quantum wells

Spin-polarized electric currents in diluted magnetic semiconductor heterostructures induced by terahertz and microwave radiation

Contact Info

Product

Resources

About